The elbow joint undergoes a lot of stress when throwing motions are repeated without alloting the proper time for healing and rest. If the tendons and ligaments on the inner side of the elbow are stretched repeatedly while the outer side of the elbow's structures are compressed, this can lead to damaged bone and tissues. This damage is especially likely to occur if the bones have not finished developing, as would be the case in a young athlete.
Medial Epicondylitis, known also as golfer's elbow, is a condition caused by overuse of the forearm's tendons and muscles. This overuse gradually deteriorates the common flexor tendon, which attaches to the media epicondyle on the inner side of the elbow. Often conservative treatments can benefit this condition.
The Medial Ulnar Collateral Ligament, or MUCL, can be found between the ulna and the the humerus on the inner side of the elbow. Symptoms of this injury generally include pain in this area. This ligament can be sprained or torn from repetitive throwing. A type of reconstructive surgery called Tommy John surgery may be required if the ligament is completely torn.
Commonly called Little League elbow, this is a condition that usually occurs before puberty. Growth plates are material on the ends of bones in children that allow the bones to expand while the child finishes growing. Damage from repetitive throwing can affect not only ligaments, but also the the growth plates. This can cause painful inflammation on the elbow's inner side. Surgery may be required if the condition is very severe.
The blood supply to the cartilage in the elbow can be disrupted by repetitive throwing. This can force areas of cartilage and bone to pull away or apart. Symptoms of this condition can include pain on the outer side of the elbow, as well as clicking or locking of the joint. Loose fragments may need to be removed surgically.